Another idea, if this will work:
Use an URL shortener to shorten your starting url
https://www.eso-skillfactory.com/de/...-import/?data=
to something like
https://short.url/12345
Depending on the shortened url it might be saving a bit space as well.
But the downside would be that users couldn't see the direct url that opens. But to be true I guess most wouldn't care